A heat treatment process for high carbon steel ingot before forging

Abstract

The application discloses a high-carbon steel spectral standard sample ingot pre-forging heat treatment process and relates to the technical field of smelting. The pre-forging heat treatment process comprises the following steps: step one, placing a smelted and cast ingot into a heat treatment furnace, sending power to heat and raise the temperature to 550-650 DEG C, and keeping heat for 15 hours; step two, after the heat keeping is finished, stopping power supply and cooling the furnace to 400-500 DEG C; step three, sending power to heat and raise the temperature to 1100-1200 DEG C, and keeping heat for 10-15 hours; step four, after the heat keeping is finished, air cooling to room temperature; step five, sending power to heat and raise the temperature to 750-950 DEG C, and keeping heat for 2-4 hours; step six, after the heat keeping is finished, air cooling to room temperature; in steps one, three and five, the temperature raising speed is controlled to be 50-100 DEG C / h; and in step two, the temperature lowering speed is controlled to be less than 100 DEG C / h. The high-carbon steel spectral standard sample prepared by the application has good standard sample component uniformity and high reliability.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of smelting, in particular to a high-carbon steel spectroscopic standard sample ingot pre-forging heat treatment process. BACKGROUND

[0002] At present, in the production process of spectroscopic standard samples, there are more researches and reports on fixed value analysis, and less researches on production process, especially the pre-forging heat treatment process of high-carbon steel. The uniformity of elements such as C and S in the high-carbon steel spectroscopic standard samples on the market is poor, and some high-carbon steels have high requirements for composition accuracy. The common spectroscopic standard samples cannot meet the requirements. High-carbon steel is a kind of steel containing a high percentage of carbon and a small amount of other elements. The high-carbon content makes this kind of steel more solid and harder than other types of steel, and it is often used to manufacture tools such as knives and abrasives. Compared with ordinary low-carbon steel, the ingot of high-carbon steel is more prone to defects such as coarse grains, segregation, porosity and pores, and white spots are also easy to form after forging. Using the existing production process of high-carbon steel spectroscopic standard samples, the ingot is forged into a rod, and the element distribution in the rod is uneven, resulting in poor uniformity of alloy elements in the finally prepared high-carbon steel spectroscopic standard sample, which seriously affects the quality of the spectroscopic standard sample. SUMMARY

[0003] The present application is to overcome the shortcomings of the prior art, and provides a high-carbon steel spectroscopic standard sample ingot pre-forging heat treatment process, which solves the problems of uneven composition distribution and poor quality of the existing high-carbon steel spectroscopic standard sample.

[0004] The technical scheme adopted by the present application to solve the technical problems is as follows:

[0005] A high-carbon steel spectroscopic standard sample ingot pre-forging heat treatment process, the pre-forging heat treatment process comprises the following steps: step one, placing the smelted and cast ingot into a heat treatment furnace, sending power to heat to 550-650 DEG C, and keeping warm for 15h; step two, after keeping warm, stopping power supply and cooling the furnace to 400-500 DEG C; step three, sending power to heat to 1100-1200 DEG C, and keeping warm for 10-15h; step four, after keeping warm, air cooling to room temperature; step five, sending power to heat to 750-950 DEG C, and keeping warm for 2-4h; step six, after keeping warm, air cooling to room temperature.

[0006] Preferably, in the step one, the temperature rising speed is controlled to be 50-100 DEG C / h.

[0007] Preferably, in the step two, the temperature falling speed is controlled to be less than 100 DEG C / h.

[0008] Preferably, in the step three, the temperature rising speed is controlled to be 50-100 DEG C / h.

[0009] Preferably, in the step five, the temperature rising speed is controlled at 50-100℃ / h.

[0010] The present application has the following advantages: 1. The present application provides a high-carbon steel ingot heat treatment process before forging, which creatively heat treats the high-carbon steel ingot before forging to improve the casting defects in the ingot; the ingot treated by the method is forged into a rod, and then the spectral standard sample is prepared, the sample composition is uniform and reliable, the quality of the spectral standard sample is ensured, and the efficiency of the sample composition detection work is improved. BRIEF DESCRIPTION OF DRAWINGS

[0011] The present application will be further described below with reference to the accompanying drawings:

[0012] Figure 1 The present application provides a high-carbon steel ingot heat treatment process before forging, which creatively heat treats the high-carbon steel ingot before forging to improve the casting defects in the ingot; the ingot treated by the method is forged into a rod, and then the spectral standard sample is prepared, the sample composition is uniform and reliable, the quality of the spectral standard sample is ensured, and the efficiency of the sample composition detection work is improved. DETAILED DESCRIPTION

[0013] In order to make the personnel in the technical field better understand the technical solutions in the present application, the technical solutions in the present application will be clearly and completely described below with reference to the accompanying drawings.

[0014] The present application provides a high-carbon steel ingot heat treatment process before forging, which creatively heat treats the high-carbon steel ingot before forging to improve the casting defects in the ingot; the ingot treated by the method is forged into a rod, and then the spectral standard sample is prepared, the sample composition is uniform and reliable, the quality of the spectral standard sample is ensured, and the efficiency of the sample composition detection work is improved.

[0015] Step one, the ingot melted and cast is put into a heat treatment furnace, and is heated to 550-650℃ by power supply, and is kept for 15h;

[0016] Step two, after the keeping, the furnace is powered off and cooled to 400-500℃;

[0017] Step three, the temperature is raised to 1100-1200℃ by power supply, and is kept for 10-15h; Step four, after the keeping, the temperature is air-cooled to room temperature;

[0018] Step five, the temperature is raised to 750-950℃ by power supply, and is kept for 2-4h; Step six, after the keeping, the temperature is air-cooled to room temperature; thus the whole ingot heat treatment process before forging is completed; then the forging or rolling process is carried out, and the block spectral standard sample is obtained by machining. Figure 1 The heat treatment process curve of the present application is shown in

[0019] In the above pre-forging heat treatment process, the high-carbon steel spectroscopic standard sample ingot in step one is prepared by induction furnace smelting. The heating process in step one is controlled at a heating rate of 50-100℃ / h; the heating process in step three is controlled at a heating rate of 50-100℃ / h; the heating process in step five is controlled at a heating rate of 50-100℃ / h; and the cooling rate in step two is controlled to be less than 100℃ / h.

[0020] To further illustrate the present application, a high-carbon steel spectroscopic standard sample ingot pre-forging heat treatment process is described in detail below in combination with examples.

[0021] Example one

[0022] A high-carbon steel spectroscopic standard sample ingot pre-forging heat treatment process, the steps are as follows:

[0023] Step one, place the ingot into a heat treatment furnace, and send power to heat to 650℃, and keep for 15h; the heating rate is 100℃ / h; step two, after the end of the heat preservation, stop the power supply and cool down to 450℃ with the furnace; the cooling rate is less than 100℃ / h; step three, send power to heat to 1100℃, and keep for 10h; the heating rate is 100℃ / h; step four, after the end of the heat preservation, air cool to room temperature; step five, send power to heat to 850℃, and keep for 3h; the heating rate is 100℃ / h; step six, after the end of the heat preservation, air cool to room temperature.

[0024] Example two

[0025] A high-carbon steel spectroscopic standard sample ingot pre-forging heat treatment process, the steps are as follows:

[0026] Step one, place the ingot into a heat treatment furnace, and send power to heat to 550℃, and keep for 15h; the heating rate is 50℃ / h; step two, after the end of the heat preservation, stop the power supply and cool down to 400℃ with the furnace; the cooling rate is less than 100℃ / h; step three, send power to heat to 1200℃, and keep for 15h; the heating rate is 100℃ / h; step four, after the end of the heat preservation, air cool to room temperature; step five, send power to heat to 950℃, and keep for 4h; the heating rate is 100℃ / h; step six, after the end of the heat preservation, air cool to room temperature.

[0027] The pre-forging heat treatment process of the ingot is carried out by the present application, and the sample after forging is sampled and subjected to uniformity detection, and the detection results are shown in Tables 1, 2 and 3.

[0028] To better reflect the progress of the present application, the following with the current high carbon steel spectral standard sample production process as a comparative example. The main production process of the current high carbon steel spectral standard sample is as follows: using intermediate frequency furnace smelting, then casting into ingot, the ingot is directly forged into a diameter of 40-50mm bar, then testing and setting value, finally machining into a spectral standard sample with a diameter of 35-40mm and a height of 35-40mm. The production process of the above high carbon steel spectral standard sample, that is, the ingot is not subjected to the heat treatment process before forging, and is directly forged. The sample after forging is sampled and subjected to uniformity detection, and the detection results are shown in Tables 4, 5 and 6.

[0029] Table 1 Uniformity detection results of steel ingot treated by using heat treatment process before forging

[0030]

[0031] Table 2 Uniformity detection results of steel ingot treated by using heat treatment process before forging

[0032]

[0033] Table 3 Uniformity detection results of steel ingot treated by using heat treatment process before forging

[0034]

[0035] Table 4 Uniformity detection results without using heat treatment process before forging

[0036]

[0037] Table 5 Uniformity detection results without using heat treatment process before forging

[0038]

[0039] Table 6 Uniformity detection results without using heat treatment process before forging

[0040]

[0041] The RSD in the above table is the relative standard deviation, and the SD is the standard deviation. Tables 1-3, 4-6 are the same ingot; by comparing the uniformity detection results of Tables 1-3 and 4-6, the uniformity detection results of Tables 1-3 are qualified and good, and the uniformity of Tables 1-3 is obviously better than that of Tables 4-6. By using the heat treatment process of the present application, the high carbon steel ingot is creatively heat treated before forging, the alloy element segregation in the ingot is improved, the hydrogen content in the ingot is reduced, the grain is refined, the casting defects in the ingot are improved, and the element uniformity of the high carbon steel spectral standard sample is improved.

[0042] The above describes the preferred embodiments of the present application, and the description of the specific examples is only for better understanding the idea of the present application. For the ordinary skilled in the art, several improvements or equivalent replacements can be made according to the principles of the present application, and these improvements or equivalent replacements are also considered to fall within the protection scope of the present application.

Claims

1. A process for heat treatment of ingot before forging of high carbon steel spectral standard sample, characterized by, The pre-forging heat treatment process comprises the following steps: Step one, put the smelted and cast ingot into a heat treatment furnace, and send electricity to heat and raise the temperature to 550-650℃, and keep the temperature for 15h; Step two, after the temperature keeping, stop the furnace and cool down to 400-500℃; Step three, send electricity to heat and raise the temperature to 1100-1200℃, and keep the temperature for 10-15h; Step four, after the temperature keeping, air cool to room temperature; Step five, send electricity to heat and raise the temperature to 750-950℃, and keep the temperature for 2-4h; Step six, after the temperature keeping, air cool to room temperature; In the step one, control the temperature raising speed to be 50-100℃ / h; In the step two, control the temperature lowering speed to be less than 100℃ / h.

2. The ingot forging pre-heat treatment process for high carbon steel spectral standard sample according to claim 1, characterized in that, In the step three, control the temperature raising speed to be 50-100℃ / h.

3. A process for heat treatment of ingot before forging of a high carbon steel spectral standard sample as claimed in claim 1, wherein the process is characterized by, In the step five, control the temperature raising speed to be 50-100℃ / h.

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